1. Field of the Invention
The present invention relates to an image forming apparatus and a power supply control method performed in the image forming apparatus.
2. Description of the Related Art
In recent years, electronic apparatuses such as digital cameras have become common that can be driven not only by supply of power from a commercial power supply outside of an apparatus body via an AC adapter, but also by supply of power from a battery removably installed in the apparatus body.
Some of the battery-drivable electronic apparatuses can switch the data transfer rate between the case of being driven by supply of power from the commercial power supply and the case of being driven by supply of power from the battery.
Japanese Laid-open Patent Publication No. 2004-118343 discloses an electronic apparatus that is configured to be capable of switching the data transfer rate to reduce power consumption. The electronic apparatus disclosed in Japanese Laid-open Patent Publication No. 2004-118343 transfers data at a rate in a high-speed mode with higher power consumption when being driven by supply of power from the commercial power supply, and at a rate in a low-speed mode with lower power consumption when being driven by supply of power from the battery.
However, the electronic apparatus disclosed in Japanese Laid-open Patent Publication No. 2004-118343 merely transfers data at the rate in the low-speed mode when being driven by supply of power from the battery, and cannot further reduce the power consumption. This causes a problem in that the duration of the battery cannot be extended.
Therefore, there is a need to provide an image forming apparatus and a power supply control method that are capable of reducing the power consumption when the apparatus is driven by an auxiliary power supply.